1. Field of the Invention
The present invention relates to a cleaning composition, a cleaning process and a process for producing a semiconductor device.
2. Description of the Related Art
In the manufacture of a semiconductor integrated circuit, larger scale integration, higher density integration and finer line-width integration are proceeding. The manufacture of a integrated circuit adopts lithography process using a positive-type or a negative-type photoresist. A photoresist film formed on a semiconductor substrate is exposed through an exposing master such a photomask. A pattern formed by a photochemical reaction in the resist film results in a resist pattern corresponded to the image pattern of the exposing master by a development. In order to improve an anti-etching stability of the resist pattern, a post-baking or an UV curing are carried out as necessary. Subsequently, using the obtained resist pattern as a mask, an etching or an ion injection are carried out to the semiconductor substrate.
When a metal layer or an insulating layer of the semiconductor substrate is etched by plasma etching using the resist pattern as a mask, residue derived from the photoresist, the metal layer or the insulating layer occur above the semicondutor substrate. In order to remove the residue occurred above the substrate by plasma etching, a cleaning is carried out using a cleaning composition.
Subsequently a resist pattern, which has become unnecessary, is removed from the semiconductor substrate. Examples of the removal method include a wet method using a stripping solution and a dry method using a plasma ashing. In the plasma ashing method, the resist pattern is ashed in a vacuum chamber by way of oxygen plasma accelerated by an electronic field in the direction of the electric field. In order to remove the residue occurred above the substrate by plasma ashing, a cleaning by using a cleaning composition is carried out. Hereinafter the residue occurred by plasma etching or the plasma ashing may be also called as ‘plasma etching residue’.
For example, JP-A-11-316465 (JP-A denotes a Japanese unexamined patent application publication) discloses a post-ashing processing solution comprising 0.5 to 10 wt % of (a) a lower alkyl quaternary ammonium salt and 1 to 50 wt % of (b) a polyhydric alcohol.
Furthermore, JP-A-2000-214599 discloses a resist stripping agent composition comprising a polyvalent carboxylic acid and/or a salt thereof and water, the composition having a pH of less than 8.